Biomedical subjects

S Lee

Publications and source records attributed to S Lee.

At least 73 records · Page 4Linked to original sources

PubMed2005

Laparoscopic adjustable gastric banding for the treatment of morbidly obese patients: early outcome in a Chinese cohort.

OBJECTIVE: To evaluate the efficacy of laparoscopic adjustable gastric banding in the management of morbid obesity in a cohort of Chinese patients. DESIGN. Cohort study. SETTING: University teaching hospital, Hong Kong. PATIENTS: From August 2002 to September 2003, 10 patients (6 male, 4 female) with a median age of 34 years (range, 23-48 years) underwent laparoscopic adjustable gastric banding to treat morbid obesity. Considerable co-existing diseases were present in 90% of the cases. We instituted a team approach that allowed every patient to see our dietitian, physician, psychiatrist (if necessary), and surgeon prior to deciding on the procedure to be used. MAIN OUTCOME MEASURES: Excessive body weight loss, quality-of-life score (SF36), and co-morbidities improvement. RESULTS: The 10 patients had a median weight of 127 kg (range, 115-196 kg) and median body mass index of 47 kg/m(2) (range, 38-67 kg/m(2)). The operation was successful in all patients with a median operating time of 110 minutes (range, 75-240 minutes). The median hospital stay was 3 days (range, 3-4 days) and three of the patients required overnight observation in the intensive care unit because of severe sleep apnoea and asthma. The median follow-up period was 12 months (range, 1-18 months). The mean weight loss at 6, 12, and 18 months was 19.3, 22.4, and 25.9 kg, respectively. Mean percentage of excessive weight loss at 6, 12, and 18 months was 34.9%, 36.5%, and 40.5%, respectively. Unsatisfactory weight loss (<20 kg) occurred in three patients because of poor dietary compliance and non-follow-up. Surgery also considerably improved the patients' co-morbidities (hypertension, diabetes, and obstructive sleep apnoea) and the quality of life. CONCLUSION: In the short term, laparoscopic adjustable gastric banding is certainly an effective procedure for morbid obesity, which results in a substantial weight loss and improvement of co-existing morbidities. Longer follow-up will show whether this weight loss is maintainable.

Adult↗

PubMed2005

A prospective evaluation of health-related quality of life in Hong Kong Chinese patients with chronic non-cancer pain.

OBJECTIVE: To evaluate the health-related quality of life in Hong Kong Chinese patients with chronic non-cancer pain. DESIGN: Prospective cross-sectional survey. SETTING: Regional public hospitals, Hong Kong. PATIENTS: Patients attending out-patient pain management clinics between 1 July 2002 and 28 February 2003 were approached to complete a set of standardised questionnaires. MAIN OUTCOME MEASURES: Demographic profiles, treatment modality, litigation, compensation, social welfare status, Hospital Anxiety Depression Scale, and Medical Outcomes Survey short-form health survey (SF36). RESULTS: Data from 166 patients were analysed. The median numeric pain rating score was 6 (interquartile range, 2-10). Work-related injury occurred in 34.3% of patients, while another 34% were involved in pain-related litigation and 32% were receiving disability or unemployment benefit. Sixty-four percent of patients were managed by three or more disciplines, while 54.8% were also receiving complimentary alternative medical treatment, mainly traditional Chinese medicine (49.7%). The Hospital Anxiety Depression Score indicated clinical anxiety or depression in 71.1% of patients. All SF36 subscale scores were lower than the local population norm. Unemployed patients had higher depression scores (P = 0.005), while students or retirees had lower physical functioning scores (P = 0.004). Patients who were single had higher role emotion scores than those who were married or separated/widowed (P = 0.011). Logistic regression analysis showed that younger age (odds ratio = 0.95), being married (6.62), work-related injury (15.63) or higher general scores (1.03) were more likely to be associated with litigation. Social welfare benefit was associated with unemployment (3.39) and a lower level of physical functioning (0.98). CONCLUSION: There was a high prevalence of clinical anxiety, depression, and severe impairment in the health-related quality of life in Hong Kong Chinese patients with chronic non-cancer pain. Specific factors affected the health-related quality of life, likelihood of litigation, and social benefit.

Adult↗

PubMed2005

Influence of floc structure on membrane permeability in the coagulation-MF process.

The relation between floc structure and membrane permeability was studied in a coagulation-MF hybrid process. The floc structure changed with operating parameters in the coagulation process and was quantified with fractal dimension (dF). The concentration ratio between suspended colloids and injected coagulant had an essential effect on dF of coagulated flocs. Larger flocs with low fractal dimension were produced for ALT (aluminum ion concentration dosed/suspended particle concentration) between 0.4 and 0.8. Flocs maintained stable characteristics at the coagulation period of over 20 minutes. Membrane permeability was improved with coagulated flocs of lower fractal dimension, which tend to have higher porosity and aggregate relatively loosely. These more porous flocs reduce specific resistance of coagulated flocs. The relation between membrane filterability and fractal dimension of flocs was explored in a submerged MF hybrid system as well as in a batch unstirred cell filtration.

Aluminum↗

PubMed2005

Scale formation in NF/RO: mechanism and control.

Scale formation of soluble salts is one of the major factors limiting the application of nanofiltration (NF) and reverse osmosis (RO) membranes. This article reviews the scale formation mechanisms in membrane systems, methods to retard scale formation, and a new hybrid system consisting of MF-NF/RO. Two distinct mechanisms in NF/RO fouling by scale formation including surface and bulk crystallization have been identified and investigated. The hydrodynamic operating conditions as well as module geometry determines which fouling mechanism is dominant. An increase in solute concentration at the membrane surface by concentration polarization is responsible for surface crystallization. Conventional methods for scale control only retard the rate of scale formation and their performances are unpredictable. On the other hand, using a MF-NF/RO hybrid system for continuous removal of crystal particles from the retentate stream appears to be effective at high recovery of permeate. When applying the MF-NF/RO hybrid system, substantial improvement in flux is observed in spiral wound module, whereas it is negligible in case of the tubular module. This is because the microfilter could only removes crystals formed in the retentate through the bulk crystallization that is the dominant fouling mechanism in the spiral wound module.

Equipment Failure↗

PubMed2005

Removal of endocrine disruptors using homogeneous metal catalyst combined with nanofiltration membrane.

Chemicals that are known or suspected of being endocrine disrupting chemicals (EDCs) have received increased attention over the past decade for their potential presence in drinking water sources. This study focuses on the development of a hybrid system that combines the advantages of nanofiltration (NF) and homogeneous catalytic oxidation, which include compactness, operational facilitation, high treatment efficiency, and selective reaction capability. Iron(lll)-tetrasulfophthalocyanine (Fe-TsPc) was employed as a homogeneous metal catalyst to degrade bisphenol-A (BPA), a representative EDC. The treatment efficiency of BPA as well as operational characteristics of the hybrid system was investigated to examine the applicability of this technique to decrease the concentration of EDCs in drinking water. Fe-TsPc homogeneous catalyst revealed a remarkable activity in degrading BPA under acidic condition. The high rejection of Fe-TsPc catalyst in the feed stream by the membrane for its large molecular weight (976 Da) and functional group (SO3(-) X4) allowed the continuous use of the catalyst for BPA oxidation reaction. The NF with Fe-TsPc/H2O2 hybrid system turned out to have higher BPA treatment efficiency comparing with the NF-only system since the hybrid system reduced BPA concentration in the feed stream by catalytic destruction of BPA as well as it mitigated concentration polarization on the surface of the membrane.

Benzhydryl Compounds↗

PubMed2005

Benign metastasising leiomyoma: a rare but possible cause of bilateral pulmonary nodules in Chinese patients.

We report three cases of benign metastasising leiomyoma, which is a rare cause of multiple lung nodules, in three Hong Kong Chinese females. One patient presented with pleuritic chest pain, another was asymptomatic, while the last presented with haemoptysis. All three patients had previously undergone surgical resection of uterine leiomyomas. Multiple lung nodules mimicking lung metastases were demonstrated on chest radiographs, and all three diagnoses were obtained from lung biopsies. Hormonal therapy was given to two patients with variable responses. To the best of our knowledge, this is the first report of benign metastasising leiomyoma in Hong Kong Chinese population. It highlights the importance of considering this rare and benign disease in premenopausal females presenting with multiple lung nodules.

Adult↗

PubMed2005

A case of Streptococcus mitis endocarditis successfully treated by linezolid.

We report the successful treatment of infective endocarditis caused by Streptococcus mitis with linezolid in a patient with pre-existing valvular heart disease. The patient had multiple allergies to conventional antibiotics. Linezolid may provide an oral alternative in the treatment of infective endocarditis in patients with adverse drug reactions to traditional antibiotic regimens.

Acetamides↗

PubMed2005

Angiopoietin-1 reduces iopromide-induced endothelial cell apoptosis through activation of phosphatidylinositol 3'-kinase/p70 S6 kinase.

Radiocontrast media can induce vascular endothelial cell apoptosis. Apoptotic damage to the vascular endothelium is an important mechanism in vascular disease. Several growth factors with anti-apoptotic effects may help protect the vascular endothelium from apoptosis. The present study evaluated whether the radiocontrast agent iopromide induces apoptosis in human umbilical vein endothelial cells and also whether angiopoietin-1 (Ang1) protects against iopromide-induced apoptosis through the p70 S6 kinase-dependent signaling pathway. Iopromide induced apoptosis in vascular endothelial cells in a dose-dependent manner. Ang1 reduced iopromide-induced apoptosis in a dose-dependent manner. Wortmannin and LY294002, phosphatidylinositol 3'-kinase inhibitors, decreased the Ang1-induced anti-apoptotic effect. Ang1 mediates the activation of mTOR/ribosomal protein p70 S6 kinase through phosphatidylinositol-3' kinase. Wortmannin and rapamycin, an inhibitor of mTOR, suppressed Ang1-induced p70 S6 kinase phosphorylation and partially inhibited the Ang1-induced anti-apoptotic effect. These results suggest that Ang1 may protect vascular endothelial cells from iopromide-induced apoptosis through phosphatidylinositol 3'-kinase and mTOR/S6 kinase. Pretreatment with Ang1 could help maintain normal vascular endothelial cell integrity before and during systemic radiocontrast administration.

Analysis of Variance↗

PubMed2004

Autosomal dominant congenital non-progressive ataxia overlaps with the SCA15 locus.

BACKGROUND: Most patients with pure nonprogressive congenital cerebellar ataxia have a sporadic form of unknown heredity and etiology. Several small families have been reported with a dominantly inherited nonprogressive congenital ataxia (NPCA). METHODS: The authors ascertained and clinically characterized a four-generation pedigree segregating an autosomal dominant type of congenital nonprogressive cerebellar ataxia associated with cognitive impairment. Following the exclusion of several SCA localizations (SCA-1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 17, IOSCA, and DRPLA), a genome-wide linkage study was performed. RESULTS: Examination of the family showed that all affected members had gait ataxia and cognitive disability with variable features of dysarthria, dysmetria, dysdiadochokinesia, nystagmus, dystonic movements, and cerebellar hypoplasia on imaging. Clinical signs of pyramidal tract dysfunction and sensory changes were absent. A genome-wide search in this family detected linkage to chromosome 3p with a maximum two-point lod score of 4.26 at D3S3630. This localization to the pter is distal to D3S1304, as defined by a recombination event. This overlaps with the SCA15 locus, with the critical overlapping region between the microsatellite markers, D3S1304 and D3S1620 (approximately 8 cM). CONCLUSION: Autosomal dominant congenital nonprogressive cerebellar ataxia with or without cerebellar hypoplasia overlaps with the SCA15 locus on chromosome 3pter.

Adolescent↗

PubMed2004

Kohn anomaly in MgB2 by inelastic X-ray scattering.

We study phonons in MgB2 using inelastic x-ray scattering (1.6 and 6 meV resolution). We clearly observe the softening and broadening of the crucial E(2g) mode through the Kohn anomaly along GammaM, in excellent agreement with ab initio calculations. Low temperature measurements (just above and below T(c)) show negligible changes for the momentum transfers investigated and no change in the E(2g) mode at A between room temperature and 16 K. We report the presence of a longitudinal mode along GammaA near in energy to the E(2g) mode that is not predicted by theory.

Journal Article↗

PubMed2004

Cranial variation in British mustelids.

Nineteen measurements were made on 136 skulls belonging to seven mustelid species: Meles meles (Eurasian badger), Mustela nivalis, (weasel), Mustela erminea (stoat), Mustela putorius (polecat), Lutra lutra (otter), Mustela furo (ferret), and Mustela vison (American mink), and polecat-ferret hybrids. To investigate shape, size-related effects were eliminated by dividing all measurements by their geometric means. Canonical variate analysis was used to reveal major interspecies distinctions. Excluding the ferrets and polecat-ferrets from the analysis, only 3.2% of the skulls misclassified (one mink, one weasel, and two stoats). Three groups separated on the first canonical axis: 1) badgers, 2) polecats, mink, and otters, and 3) stoats and weasels. The important variables were width of zygomatic arch and height of sagittal crest opposed to the postorbital distance, condylobasal length, and basilar length. Otters separated out on the second canonical axis; the most important variables were postorbital breadth and width of the postorbital constriction opposed to the basioccipital width. There was reasonable separation of polecats from mink on a combination of the second and third canonical axes. On the latter the most important variables were postorbital breadth opposed to postorbital distance. Addition of the ferret data showed that they lay closest to, and overlapped with, the polecats. The stoat and weasel data alone gave complete separation, with height of sagittal crest and width of zygomatic arch opposed to basioccipital width. However, using size-in data the best separation was the relationship between postorbital breadth and either basioccipital width or postorbital distance. Sexual dimorphism was demonstrated in the skulls of badgers but was shown to be relatively insignificant when compared to the interspecific differences.

Anatomy, Comparative↗

PubMed2004

Use of autotrophic sulfur-oxidizers to remove nitrate from bank filtrate in a permeable reactive barrier system.

This study was conducted to evaluate the potential applicability of an in situ biological reactive barrier system to treat nitrate-contaminated bank filtrate. The reactive barrier consisted of sulfur granules as an electron donor and autotrophic sulfur-oxidizing bacteria as a biological component. Limestone was also used to provide alkalinity. The results showed that the autotrophic sulfur oxidizers were successfully colonized on the surfaces of the sulfur particles and removed nitrate from synthetic bank filtrate. The sulfur-oxidizing activity continuously increased with time and then was maintained or slightly decreased after five days of column operation. Maximum nitrate removal efficiency and sulfur oxidation rate were observed at near neutral pH. Over 90% of the initial nitrate dissolved in synthetic bank filtrate was removed in all columns tested with some nitrite accumulation. However, nitrite accumulation was observed mainly during the initial operation period, and the concentration markedly diminished with time. The nitrite concentration in effluent was less than 2 mg-N/l after 12 days of column operation. When influent nitrate concentrations were 30, 40, and 60 mg-N/l and sulfur content in column was 75%, half-order autotrophic denitrification reaction rate constants were 31.73 x 10(-3), 33.3 x 10(-3), and 36.4 x 10(-3) mg(1/2)/l(1/2)min, respectively. Our data on the nitrate distribution profile along the column suggest that an appropriate wall thickness of a reactive barrier for autotrophic denitrification may be 30 cm when influent nitrate concentration is less than 60 mg-N/l.

Hydrogen-Ion Concentration↗

PubMed2004

Mycelial culture of Phellinus linteus protects primary cultured rat hepatocytes against hepatotoxins.

Hepatoprotective activity of Phellinus linteus was studied using H(2)O(2)- or galactosamine-injured primary cultures of rat hepatocytes as screening systems. The methanolic extract of the mycelial culture of Phellinus linteus significantly protected against hepatotoxins-induced toxicity in primary cultured rat hepatocytes as seen from the decreased level of glutamic pyruvic transaminase released from the injured hepatocytes. The methanolic extract of the mycelial culture of Phellinus linteus was subsequently fractionated with n-hexane, ethyl acetate, n-butanol and water. Among these fractions, 100 microg/mL of the ethyl acetate fraction was the most active one. The relative protections were 68.9 +/- 5.3% in H(2)O(2)-injured hepatocytes and 46.8 +/- 3.9% in galactosamine-injured hepatocytes, respectively. The ethyl acetate fraction appeared to maintain the glutathione level which was decreased by the treatment of H(2)O(2) or galactosamine and restored the level of RNA synthesis more than two times compared to galactosamine-injured hepatocytes. These results suggest that the ethyl acetate fraction of the mycelial culture of Phellinus linteus protects hepatocytes from H(2)O(2)- or galactosamine-induced injury by maintaining hepatic glutathione level and RNA synthesis as well.

Animals↗

PubMed2004

Associations with Vitamin D deficiency in "at risk" Australians.

In a study of 185 elderly living in assisted care and 192 frail aged living in the community in the Sydney metropolitan area, nursing home residents were found to be at a 3-fold and hostel dwellers at a 2-fold risk of Vitamin D [25(OH)D] deficiency (<25 nmol/L) compared to self care residents. Middle Eastern people were found to be at 4-fold risk and Vietnamese a 3-fold risk of deficiency compared to their Australian counterparts. In recently arrived Chinese immigrants, Vitamin D deficiency, was found in 28%, and marginal levels (<37 nmol/L) in 60%, compared to the 34 and 76% found in our nursing home population, and 25 and 57% in hostel care residents. Of the Middle Eastern elderly, 58% were deficient and 83% marginal; although only 18% of Vietnamese were deficient, 68% had marginal Vitamin D status. Other factors associated with Vitamin D deficiency were mobility and sun exposure in assisted care, and low dietary Vitamin D and calcium intake, reduced exercise levels and high % body fat levels in the immigrant groups.

Aged↗

PubMed2004

Simulect and HHV-6 in pediatric renal transplantation.

Herpes virus reactivation is of increasing interest as we aim to decrease morbidity and mortality in the pediatric renal transplant population. We previously reported increased reactivation of HHV-6 and Epstein Barr virus (EBV) with anti-thymocyte globulin/ALG induction therapy. HHV-6 reactivation and de novo infection has been monitored in 31 consecutive pediatric renal transplant patients receiving antibody induction with Simulect. Human Herpes virus-6 (HHV-6) was correlated with EBV reactivation and de novo infection rates, allograft function at 1 year, donor source and number, and patient age and gender. One HHV-6 de novo infection was associated with an early grade II rejection that was steroid resistant but ATG/ALG responsive. Sixteen of 31 (54.8%) patients had HHV-6 reactivation during the first year and eight patients had a prior reactivation profile before transplant. Thirteen patients (41.9%) were naïve to EBV infection prior to transplant with evidence of primary infection in 11 of 13 patients between 6 weeks and 1 year posttransplant. EBV reactivation was noted in four patients with past immunity to EBV. IgM Ab to EBV or HHV-6 during the first year posttransplant did not correlate with risk of rejection during the first year or graft function one year posttransplant. The only patient with positive HHV-6 IgM Ab in the first posttransplant month was a de novo infection in a 2-year-old boy who was naïve for HHV-6 at the time of transplant. Simulect appears safe in pediatric renal transplant with low risk of HHV-6 or EBV infection in the first 1 to 2 months posttransplant.

Adrenal Cortex Hormones↗

PubMed2004

Cytogenetic clonal evolution alone in CML relapse post-transplantation does not adversely affect response to imatinib mesylate treatment.

Good prognosis after imatinib mesylate treatment has been reported if cytogenetic clonal evolution (CE) is the only criterion of accelerated phase (AP) chronic myelogenous leukemia (CML). To evaluate the impact of CE upon imatinib treatment in post-transplant settings, responses and toxicities in the relapsed AP-CE were analyzed in comparison with those in the relapsed chronic phase (CP). Both CP (n=7) and AP-CE patients (n=6) received imatinib mesylate in an oral dose of 400 mg/day. Complete cytogenetic responses were obtained in six patients of each group, CP (86%) and AC-CE (100%), while molecular remission was seen in 43 and 50%, respectively. Granulocytopenia or thrombocytopenia of grade III or more occurred in four (57%) and two (33%) patients with CP and AP-CE, respectively. Nonhematological adverse events were mild and tolerable in both groups and only one (7%) of the 13 patients experienced recurrent graft-versus-host disease after imatinib treatment. Although this is a relatively small group of patients, we suggest that imatinib mesylate should be considered as a front-line treatment for relapsed CML as it showed the high response rate and low toxicity. We also suggest that CE alone is not an important factor in the induction of cytogenetic and molecular remissions in post-transplant relapse.

Adult↗

PubMed2004

Preemptive treatment of minimal residual disease post transplant in CML using real-time quantitative RT-PCR: a prospective, randomized trial.

Immunotherapy in the form of donor lymphocyte infusions in early-phase relapse might be advantageous as it induces a higher response, but this may be offset by increased toxicity, especially during the early period after transplantation. Among 45 consecutive patients receiving an allograft for CML, 13 patients were diagnosed to have molecular relapse (MRel), as defined by real-time quantitative reverse transcriptase-polymerase chain reaction, and another four patients were diagnosed to have cytogenetic relapse (CRel) within 6 months. Patients with MRel were randomly assigned to either a 'no therapy' group (group A, n=6), in which immunotherapy was reserved until CRel, or an 'immunotherapy' group (group B, n=7). In group A, all MRel progressed to CRel, and molecular remission (MR) was achieved in four (67%) after immunotherapy. The remaining two patients died of extensive GVHD and fungal pneumonia. In group B, only two MRel progressed to CRel and the remaining five (71%) achieved MR. Two patients died in the absence or loss of response. In patients relapsing directly into CRel (n=4), immunotherapy induced MR in two patients (50%). Earlier intervention played a role in preventing disease progression but this effect was not translated into better survival, which could have been overcome by imatinib mesylate, which induced MR and cytogenetic remission in nonresponders without toxicity.

Acute Disease↗

PubMed2004

Infectious complications and outcomes after allogeneic hematopoietic stem cell transplantation in Korea.

We reviewed 242 allogeneic hematopoietic stem cell transplantation (HSCT) recipients retrospectively over a 2-year period (January 1998-December 1999) in order to analyze the characteristics and assess the outcomes of infectious complications in patients after HSCT in Korea. Bacteria were the major pathogens before engraftment, and viral and fungal infections predominated during the post-engraftment period. Varicella zoster virus was the most common viral pathogen after engraftment. Cytomegalovirus disease occurred mainly in the late-recovery phase. The frequency of mold infection was higher than that of yeast. There was a relatively high incidence of tuberculosis (3.0%) and Pneumocystis carinii pneumonia (6.5%). One case of death by measles confirmed by autopsy was also noted. Overall, cumulative mortality was 43% (104/242), and 59.6% of these deaths (62/104) were infection-related. Allogeneic HSCT recipients from unrelated donors were prone to infectious complication and higher mortality than those from matched sibling (17/39 (43.6%) vs 45/203 (22.2%), respectively; P<0.01; odd ratio 2.5; 95% confidence interval 1.2-5.1). As infection was the main post-HSCT complication in our data, more attention should be given to the management of infections in HSCT recipients.

Adolescent↗